JP2004521729A - Assembly including permeable medium and frame - Google Patents

Abstract

An assembly is provided that includes a permeable medium and a frame. The permeable media includes a sintered fabric that includes metal fibers. By spraying a ceramic or metal layer on the joint between the permeable medium and the frame, a leak-proof seal is formed between the permeable medium and the frame. This assembly is particularly preferably used as a filter element.

Description

【Technical field】
[0001]
The present invention relates to an assembly comprising a permeable medium and a frame, wherein the permeable medium is secured to the frame and sealed from each other in a leak-proof manner. More particularly, the invention relates to a filter element. The invention further relates to a method of sealing a permeable medium to a frame.
[Background Art]
[0002]
In the manufacture of a filter element, it is a difficult and important process to fix and seal a filter medium to a frame which is a medium holder. In particular, in the case of a filter element made of a pleated filter medium, how to adhere the peripheral portion of the filter medium to the frame has become a major issue due to its structure.
[0003]
There are many requirements that must be met to obtain a reliable and useful filter element. First, it is essential to provide a strong leak-proof seal at the joint between the filter medium and the filter frame. The filter does not function properly at the junction, whatever the small leakage.
[0004]
In the case of a fluted filter media, the fold openings need to be closed and sealed to guide gas or liquid through the filter media from the fold inlet opening to the fold outlet opening located outside the filter media.
[0005]
Another requirement is that the filter element, and more specifically the junction between the filter media and the frame, must withstand high temperatures and / or high temperature fluctuations.
[0006]
Many techniques for sealing filter media to a frame are currently known in the art. Known methods include, for example, a method using an adhesive, a method using welding, and a method using pressure bonding.
[0007]
However, these filter elements have the disadvantage that they cannot withstand sufficiently high temperatures and sufficiently high pressures. Connections and sealing between the filter media and the frame tend to be lost due to thermal shock due to differences in the coefficients of thermal expansion between the parts connected to each other. In particular, the portions of the seal that must withstand deformation tend to be damaged. At such deformed parts, aging is accelerated, especially by pressure changes. Another drawback of many filters according to the prior art is that the seal between the filter media and the frame does not have a leak proof feature.
DISCLOSURE OF THE INVENTION
[0008]
SUMMARY OF THE INVENTION It is an object of the present invention to provide an assembly including a transparent medium and a frame that can solve the problems of the prior art. It is another object of the present invention to provide an assembly wherein the permeable medium is sealed to the frame in a fluid-tight manner. Yet another object of the present invention is to provide a permeable media and frame in which a strong seal is formed between the permeable media and the frame that is capable of withstanding high and high temperature fluctuations and / or high and high pressure fluctuations. It is to provide an assembly comprising: Yet another object of the invention is to use the assembly according to the invention as a filter element. It is another object of the present invention to provide a method of sealing a permeable medium to a frame without leaking fluid.
[0009]
According to a first aspect of the present invention, there is provided an assembly comprising a permeable medium and a frame. The permeable medium is secured to the frame and sealed to the frame by a sprayed ceramic or metal layer. A ceramic or metal layer is sprayed onto the interface between the permeable medium and the frame. The term "junction between the permeable medium and the frame" means the area where the permeable medium and the frame are in contact with each other. Also, the term "frame" refers to any structure that holds a permeable medium. The frame may be a rigid support for supporting the permeable medium.
[0010]
By providing a sprayed metal or ceramic layer, the permeable medium can be sealed to the frame without fluid leakage. If the assembly is a filter element, the application of a sprayed metal or ceramic layer can maintain the filtration grade of the filter media after it has been mounted on the frame at a predetermined value.
[0011]
The permeable medium is preferably a sintered fabric comprising metal fibers. The sintered fabric includes at least one nonwoven fabric of metal fibers, preferably stainless steel fibers.
[0012]
The metal fibers preferably have a diameter in the range from 1 μm to 100 μm. More preferably, the diameter of the metal fibers is in the range of 1 μm to 35 μm, for example 2 μm, 4 μm, 8 μm or 12 μm. The metal fibers may be obtained by any technique known in the art. For example, the metal fibers may be obtained by bundle drawing or shaving.
[0013]
The permeable medium may be a layered structure composed of a number of different layers stacked, each layer comprising a fabric of sintered metal fibers. For example, the permeable medium may be a multilayer structure including a first layer made of a metal fiber having a diameter of 4 to 10 μm and a second layer made of a metal fiber having a diameter of 2 to 4 μm.
[0014]
The choice of the permeable medium may be made according to the application. In the case of a filter element, the selection of the filter medium may be made according to the required filter properties, for example, the size of the micropores, the filtration grade, the porosity and the like.
[0015]
The permeable medium must be able to withstand sufficiently high temperatures, in particular during spraying operations.
[0016]
The metal fiber alloy may be selected to withstand the working environment of the final product. In the case of a temperature of 360 ° C. or less, a stainless steel fiber made of AISI300 series alloy, for example, AISI316L is preferable. Under the condition of 500 ° C. or less, an INCONEL (registered trademark) -based alloy, for example, a fiber made of INCONEL601 is preferable, and under the condition of 560 ° C. or less, a Hastelloy (registered trademark) -based alloy, for example, And fibers made of HASTELLOY-HR. Further, under the condition of 1000 ° C. or lower, a fiber made of an Fe—Cr—Al alloy is preferable.
[0017]
The permeable medium may also be metal particles, for example metal powder or short metal fibers.
[0018]
The permeable medium may have any shape. For example, the permeable medium may have a planar shape or a cylindrical shape. The permeable medium may be a pleated medium. Any geometric fold may be used. For example, it may be a permeable medium having folds such that the fold lines extend substantially parallel to each other. The permeable medium having other geometrical folds may be a cylindrical permeable medium that is pleated such that the fold line extends parallel to the central axis.
[0019]
As described above, the frame has a function of holding the permeable medium and / or a function of a rigid support for the permeable medium. In addition, the frame closes the fold openings in the permeable medium to prevent undesirable fluid diversion, e.g., to prevent gas or liquid from flowing from the filter inlet to the filter outlet without passing through the permeable medium. Has a function.
[0020]
The frame may include one or more outer walls, such as an inner wall and an outer wall, or may include a wall that includes two or more portions, such as an upper and lower portion. Alternatively, the frame may include one or more caps.
[0021]
The frame can be made, for example, from a metal, ceramic or plastic material.
[0022]
If the assembly is used under high temperature conditions, the frame is preferably made of a metal or metal alloy, for example, steel.
[0023]
In a preferred embodiment, the filter element comprises a frame having an upper part and a lower part. In the case of pleated media, such as pleated filter media, the upper edge in contact with the pleated filter media has the same wave shape as the pleated outer edge of the filter media. The lower edge in contact with the pleated sintered metal fiber fabric also has the same undulation as the pleated edge of the fold opening. The pleated filter media is then placed and clamped between the upper and lower parts of the frame such that the pleated opening is closed by the upper and lower edge corrugations. The top of the frame, the fluted filter media, and the bottom of the frame are joined together by spraying a ceramic or metal layer on the junction between the filter media and the frame.
[0024]
Alternatively, in other embodiments, the permeable media may be secured by a filter cap. This configuration is advantageous, for example, in the case of a filter tube. Such a filter tube may have an end cap on one or both of the upper and lower sides. By securing the filter media to the filter cap, the filter tube can be easily mounted within a more complex filter structure.
[0025]
If the assembly is used under high temperature conditions, the frame is preferably made of metal, for example, steel. More preferably, the frame is made from stainless steel.
[0026]
By spraying a ceramic or metal layer onto the interface between the permeable medium and the frame, the permeable medium is secured to the frame and sealed. A preferred technique is thermal spraying. Various spraying methods can be used, for example, flame spraying or spraying using an electric arc or plasma gun.
[0027]
The sprayed metal layer may be a layer containing any metal or metal alloy. Preferably, it is a layer containing steel, stainless steel, a zinc alloy or a nickel alloy.
[0028]
The sprayed ceramic layer includes, for example, metal oxides (such as sodium oxide, potassium oxide, aluminum oxide, zirconium oxide, and titanium oxide), carbides (such as tungsten carbide), silicates (such as sodium silicate, potassium silicate, and silicon silicate). (Such as zirconium oxide), nitrides (such as boron nitride), or mixtures thereof.
[0029]
The thickness of the spray layer is preferably in the range of 1 to 5000 μm, more preferably in the range of 1 to 1000 μm.
[0030]
The spray layer is in uniform and intimate contact with the joint between the permeable medium and the frame and forms a leak-proof seal between the permeable medium and the frame.
[0031]
This seal between the permeable medium and the frame is more reliable and more resistant to high temperature fluctuations than the seal between the medium and the frame by gluing or welding.
[0032]
In a preferred embodiment, the spraying material may be the same as the material of the permeable media and / or the filter frame. This arrangement is particularly advantageous for filter elements used under high temperature conditions or high temperature fluctuations.
[0033]
According to a second aspect of the present invention, there is provided a method of manufacturing an assembly. The method comprises the steps of providing a permeable medium, providing a frame, securing the permeable medium to the frame, and spraying a metal or ceramic layer on a junction between the permeable medium and the frame. And a process.
[0034]
The spraying is preferably thermal spraying, for example flame spraying or thermal spraying using an electric arc or plasma gun.
[0035]
The assembly according to the invention is suitable for any kind of application where it is desired that the permeable medium be fixed to the frame. The assembly according to the invention is also suitable for any application in which a leak-proof connection between the permeable medium and the frame is desired. In particular, the assembly according to the invention can be used for the filtration of all kinds of gases and liquids, for example for the filtration of water, wastewater, oils, drinks.
[0036]
Since the assembly according to the invention can withstand high temperatures and high temperature fluctuations, it is very suitable for filtering hot gases. In particular, it can be suitably used for filtering exhaust gas, for example, combustion gas. Other uses of the assembly according to the invention include, for example, catalyst carriers in exhaust systems of combustion engines. Furthermore, the assembly according to the invention can be used as a diffuser, for example an aerated diffuser.
BEST MODE FOR CARRYING OUT THE INVENTION
[0037]
Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.
[0038]
FIG. 1 shows a preferred embodiment of the assembly according to the invention. The assembly comprises a permeable medium 12 and a frame surrounding the permeable medium 12. The permeable medium consists of a sintered metal fiber fabric. This assembly is used as a filter element.
[0039]
After the permeable medium has been fixed to the frame, the metal layer 16, more specifically the stainless steel layer, is applied to either the upper or lower surface (in the example of FIG. 1b, the upper surface) or the transparent surface of the joint between the permeable medium and the frame. It is formed by thermal spraying on both the upper and lower surfaces (FIG. 1c) of the joint between the conductive medium and the frame.
[0040]
FIG. 2 shows a modification of the assembly 21 according to the present invention.
[0041]
The permeable medium 22 is made of a cylindrical filter medium. The cylindrical medium is fixed to two filter caps 24. By using these filter caps 24, the filter element can be easily mounted in a complex filter structure. Also, a layer 26 of aluminum oxide is formed by thermal spraying on each junction between the permeable medium and the cap.
[0042]
FIG. 3 shows a preferred embodiment of the filter element of the present invention. The filter media consists of a pleated sintered metal fiber fabric 31. As shown in FIG. 3, the sintered metal fiber fabric 31 has a fold such that a fold line 32 extends outward from a central axis 33. Each fold has one fold opening 34 extending outward and a second fold opening 35 extending toward a central axis 33 in the open core region 36. All outwardly extending fold openings have corrugated edges 37. Also, all fold openings toward open core region 36 have corrugated edges 38.
[0043]
As shown in FIG. 4, the outer edge 37 of the pleated sintered metal fiber fabric is located between the upper part 41 and the lower part 42 of the frame 43 and is tightened. The upper part 41 has a wavy lower end, and the lower part 42 has a wavy upper end. These corrugations correspond to the shape of the outer edge 37 of the pleated sintered metal fiber fabric. The upper portion 41 and the lower portion 42 are pressurized with the pleated sintered metal fiber fabric sandwiched therebetween.
[0044]
FIG. 5 shows a filter element 51 according to the invention comprising the filter medium and the frame shown in FIG. The two portions of the frame and the filter media are permanently joined and sealed together by spraying an Inox metal layer 52 at each junction between the filter media and the two portions of the frame. This spraying is preferably performed outside the outer wall.
[0045]
The fold opening extending towards the central axis can likewise be closed.
[0046]
6 and 7 show another embodiment. In this embodiment, the sintered metal fiber fabric 61 comprises cylindrical folds, which have fold lines 62 extending essentially parallel to one another. The fold openings 63 on both sides of the cylindrical shape are closed by two outer walls on both sides of the cylindrical shape. This configuration is obtained by inserting the lower portion 64 of the outer wall into the interior of the pleated sintered metal fiber fabric and matching the lower edge 65 to the corrugated shape 66 of the pleated sintered metal fiber fabric 61. By using the second and third upper portions 67 and 68 of the outer wall having ends that match the perimeter halves of the crimped sintered metal fiber fabric 61, the crimped sintered metal fiber fabric is joined to the three portions of the outer wall. Position it in between and tighten. A metal layer 71 is formed at the joint between the filter medium and the frame by thermal spraying.
[0047]
The pleated opening on the other side may be similarly closed by another outer wall.
[0048]
FIG. 8 shows a tubular filter element 81 including a pleated filter media 82 secured by an end cap 83. A layer 84 of stainless steel is formed by spraying on the joint between the permeable medium and the frame.
[Brief description of the drawings]
[0049]
FIG. 1 is a diagram showing an assembly including a flat permeable medium and a frame surrounding the medium.
FIG. 2 illustrates a cylindrical permeable medium held by two filter caps.
FIG. 3 is a plan view of a pleated medium.
FIG. 4 shows two parts of a filter frame for tightening the filter medium shown in FIG. 3;
FIG. 5 shows a filter element according to the invention in which a layer has been sprayed onto the joint between the filter medium and the frame.
FIG. 6 is a diagram showing a modified example of a pleated filter medium.
FIG. 7 is a diagram showing a modified example of a foldable filter medium.
FIG. 8 illustrates a pleated permeable media held by two filter caps.

Claims (18)

An assembly comprising a permeable medium and a frame, wherein the permeable medium is fixed to the frame, the permeable medium is a sintered fabric including metal fibers, and the permeable medium is An assembly wherein the ceramic or metal layer is sealed to the frame by an applied layer of ceramic or metal, the sprayed ceramic or metal layer being formed at the junction of the permeable medium and the frame. The assembly of claim 1, wherein the sprayed ceramic or metal layer forms a leak tight seal between the permeable medium and the frame. 3. The assembly according to claim 1, wherein the metal fibers have a diameter in the range of 1 to 100 [mu] m. An assembly according to any one of the preceding claims, wherein the sprayed ceramic or metal layer is formed at the junction between the permeable medium and the frame by thermal spraying. An assembly according to any of the preceding claims, wherein the sprayed metal layer comprises a metal or a metal alloy. The sprayed ceramic layer comprises a ceramic material selected from the group consisting of metal oxides, carbides, silicates, nitrides and mixtures thereof. Assembly. The assembly according to any one of claims 1 to 6, wherein the permeable medium is a planar or cylindrical medium. An assembly according to any one of the preceding claims, wherein the permeable medium is pleated. An assembly according to any one of the preceding claims, wherein the frame is made from a metal, ceramic or plastic material. An assembly according to any preceding claim, wherein the frame comprises at least one outer wall. An assembly according to any preceding claim, wherein the wall comprises an upper part and a lower part. The assembly according to any one of the preceding claims, wherein the frame comprises at least one filter cup. An assembly according to any one of the preceding claims, wherein the permeable medium is a filter medium. A method of manufacturing an assembly according to any one of claims 1 to 13,
Providing a permeable medium;
Preparing a frame,
Fixing the permeable medium to the frame;
Spraying a layer of metal or ceramic onto the junction of the permeable medium and the frame. The method according to claim 14, wherein the spraying is thermal spraying. Use of the assembly according to any one of claims 1 to 13 for filtering gas or liquid. Use of the assembly according to claim 16 for the filtration of hot gases or liquids. Use of the assembly according to claim 16 or 17 for the filtration of exhaust gases.